1. Field of the Invention
The present invention relates to non-linear transmission lines and, more particularly, to the use of the inherent non-linearity characteristics of high temperature superconductive materials in the realization of non-linear transmission lines.
2 Description of the Prior Art
It is known that wave propagation on periodically-loaded Non-Linear Transmission Lines (NLTL) leads to the generation of harmonics, each of which travels at its own phase velocity. If non-linearity and dispersion are balanced, certain unique RF characteristics can be potentially achieved, such as shock wave formation and soliton propagation. Over the past years, several papers have been published on the use of periodically-loaded non-linear transmission lines in instrumentation and pulse compression applications. NLTL""s are typically realized using a transmission line periodically loaded with varactor diodes. The non-linearity arises from the dependence of the capacitance of the varactor diodes on the voltage of the propagating wave along the transmission line.
There are other methods of achieving the required non-linearity and dispersion. For example, it has been suggested that loading a transmission line with non-linear dielectric materials can potentially lead to the realization of a NLTL (See D. Jxc3xa4ger, xe2x80x9ccharacteristics of travelling waves along the non-linear transmission lines for monolithic integrated circuits: a review, xe2x80x9dInt. J. Electronics,vol. 58, no. 4, pp. 649-669, 1995.).
NLTL""s can be conveniently realized using Monolithic Microwave Integrated Circuits (MMIC) technology. The attenuation of these lines, however, considerably limits their usefulness in many applications. NLTL""s can be also built using varactor diodes as discrete components attached to a transmission line. However, assembly of such Non-linear transmission lines is extremely difficult.
It is an object of the present invention to provide non-linear transmission lines using the high temperature superconductive technology and the non-linearity characteristics of such technology. It is a further object of the present invention to build non-linear transmission lines that have low insertion loss compared to what can be achieved using conventional MMIC technology.
A non-linear transmission line comprising a line extending between an input and an output, the line having high temperature superconductive elements periodically loaded thereon. Preferably, the elements have non-linear characteristics that provide voltage dependent non-linearity to the line.
A method of constructing a superconductive non-linear transmission line, the method comprising periodically loading HTS elements on a transmission line. Preferably, the HTS elements have non-linear characteristics that provide voltage dependent non-linearity to the line.
The foregoing and other objects and advantages of the invention will become apparent from the following description.